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Project...Bokeh Monster...Pentacon 135mm F2.8 ..."15 Blades" Zebra.
Quote: Isn' it 46.5- 45.46 =  1.04mm + 0.9mm = 1.94mm?....anyway...


   The first step will be to try the lens on the Nikon with the adapter that has the 0.9mm flange in between the lens and the camera mount and we will see what I've got...........from what I've read though I can expect a 5mt MFD......on a 135mm lens that's head and shoulders shots.......fairly constricting....and not what I had in mind......I would like to do the odd video as well........and "bathe" in that lovely transition between close focus and then focusing out to infinity with the lens fully open to reveal those otherwise mysterious backdrops.


   Plan "A" is still on!
Yes, of course 1.94mm. You are right.


MFD stands for minimum focus distance.  Wink


Of course, when you want to do what you describe, it is necessary to reach infinity. And I can't offer a trade for my 135mm f2.8 "K" Nikkor, as it has super smooth bokeh at MFD but further out it starts to be less than smooth by all accounts. And it does not have those sexy zebra stripes and no 15 aperture blades! And it would need Ai-ing anyway.


I get a further maximum focus distance though.

For 135mm and 200m focus distance I get a 1:1480 magnification. Using that magnification number in this calculator, and using 1.94mm as extension amount:

I get 9.2m maximum focus distance. So I guess it will be about 9.5 meters.

The Pentax M42-PK mount adapter turned up today,  tried it on the K01, couldn't get on with the camera's grip with that lens.......... so put it on the K3.....


   focus confirmation works great I was getting accurate focus......


  the lens is fairly sharp wide open but with plenty of sixties style flaring.... blue/purple halos.....


 most of it's gone at F4 ......F5.6/F8  is sharp across the APS frame......started to rain again....


 F2.8 with a little contrast/sharpness boost...........


 Awaiting the Nikon F adapter...........................

Dave's clichés
Finally the M42-Nikon F mount arrives!


      How do they do it?  I ordered the adapter from Japan  on ebay......0.99 cents including postage to France........
 fits very well!

Dave's clichés
Now I will be waiting for some results on your Nikon Big Grin

I took a few shots of the same lady fully open on the D750, you know, I think the results are better than the Nikor 55mm F1.2, almost hurts to say it. Huh  

 The Pentacon is way better and sharper on FF,  and shallower DOF of course.  I think I'm going to like it, also it's easier to focus, took three quick portraits and got  1 1/2 in focus. Big Grin

 The mods take place tomorrow morning, now I've got the adapter I've been able to study the plan a bit better, the lens does not seat tight on the adapter, leaving a gap of 2mm, the M42 thread ends and has a 2mm tail, so that will be the first to go. I've decided to machine the first detachable part of the barrel, basically it's just a tube so nothing will be weakened just shortened.

 I'll take a few pics of the mods, a new post in the Nikon section of course!


   Oh what fun turning down one's lens collection on a lathe!  :lol:
Dave's clichés
it's about bokeh?


[Image: _DSC0983-XL.jpg]


Oh no, it's about DIY bokeh. Sorry to interrupt...

Quote:it's about bokeh?


[Image: _DSC0983-XL.jpg]


Oh no, it's about DIY bokeh. Sorry to interrupt...
No problem.......nice..what's the optic?
Dave's clichés
Inside a room... lot to see, but maybe not to recognize...distance to main subject a bit more than 20 cm... make your guess  ^_^


Funny, here I go with all those megapixels and what do I do? Playing around with blurry pics...

Fuji 56?

Sigma 20/1.4 A Wink


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